TUNING AND CHIRPING FIBER BRAGG GRATINGS BY DEEP-ETCHING

We have demonstrated a new method for tuning and chirping fiber gratin gs, It relies on etching of a fiber down to very small cladding diamet er, so that the propagating optical mode in the fiber interacts with t he surrounding media, A tuning range of 4.5 mm has been demonstrated w ith a potential of much larger tuning range by optimization of fibers, Chirped gratings were also demonstrated with this technique, These ch irped gratings are very important for use in fiber dispersion compensa tion and optical pulse shaping.